Inboard Engines and Components

There are two types of boat engine: inboard and outboard. You’d likely recognise the outboard kind in your sleep; it features a prop that dips into the water, which can be lifted up when the boat isn’t in use, and can be steered with a single handlebar. The inboard kind, however, is built into the boat itself. This is more common for boats that are a little larger and complicated; the ones that go a little further than just being something that floats and seats four. It also makes it trickier to replace or repair the engine though. The outboard goes through the hull in places, and you need to make sure you don’t break any seals, letting in water.


Like with any type of engine, there are a lot of different inboard engine parts that help make the whole thing move and you’ll want to keep them all in good condition, too. It’s one thing for your car to stall and having to wait for roadside assistance for over an hour, it’s quite another thing to get stranded out on the water with no means of propulsion because the ignition on your engine or inboard fuel intake system failed.

In and Out

The conventional inboard propulsion engine drives a propulsion screw at the back of the boat with a driveshaft, but there’s also a hybrid approach that combines the best of in and outboard propulsion. Sterndrive propulsion combines a larger engine mounted in the middle of the boat for good weight distribution and better, safer handling, with a drive unit that’s mounted outside, making it easy to access key components for maintenance.


Inboard engine propulsion were some of the very first engines ever mounted on a ship with the coming of the first steamboats. They’ve come a long way since then, though, and today you can enjoy your boat without having to employ any soot-stained youth in overalls shovelling coal into a furnace.